Here, a phosphazene-based flame retardant (PBFA) containing active amine groups was synthesized by hexachlorocyclotriphosphazene and N-aminoethylpiperazine and nickel ion (Ni2+) was chelated to the surface of PBFA (named as PBFA-Ni2+). Incorporation into epoxy resin (EP) with a loading of 6 wt% (named as EP/PBFA-Ni2+-6.0), enabled the composite to pass the vertical burning test (UL-94) V 0 rating. Peak heat release rate and the total smoke release of EP/PBFA-Ni2+-6.0 were decreased by 41.02% and 22.74% as measured by cone calorimeter tests. The production rate of CO was inhibited when PBFA-Ni(2+)was incorporated into EP.